1. Field of the Invention
The present invention relates to heat sink assemblies, and particularly to heat sink assemblies incorporating spring-loaded standoffs.
2. Related Art
Computer electronic devices such as central processing units (CPUs) frequently generate large amounts of heat, which can destabilize operation and cause damage. A heat sink placed in thermal contact with an electronic device transfers heat from the electronic device through conduction.
U.S. Pat. No. 5,757,621 discloses a conventional heat sink assembly for attachment to a motherboard. The heat sink assembly comprises a heat sink, a plurality of top screws, a plurality of bottom screws, a plurality of standoffs, a plurality of springs and a plurality of pads. Each standoff comprises a shoulder, and a neck extending upwardly from the shoulder.
In assembly, the necks of the standoffs are extended through a base of the heat sink, and the shoulders abut the motherboard. The bottom screws are threaded through the shoulders into the necks. The springs are then slid over the necks to abut the base. The pads are placed on the springs. The top screws are threaded into the necks and compress the springs to press the heat sink onto an integrated circuit on the motherboard.
Nevertheless, the screws cannot be guided into the standoffs before the screws are threadedly engaged with threads in the standoffs. This results in undue inconvenience when threading the screws into the standoffs. Furthermore, there is an excessive number of components in the assembly, thereby inflating costs and rendering the assembly process unduly complicated.
Accordingly, an object of the present invention is to provide a heat sink assembly incorporating standoffs which can easily and conveniently guide bolts in the standoffs.
To achieve the above-mentioned object, a heat sink assembly in accordance with the present invention comprises a heat sink, a plurality of standoffs, and a plurality of springs. The heat sink comprises a base defining a plurality of through apertures. Each standoff comprises a body extending through a corresponding through aperture, and a head formed on a top end of the body. The springs are placed over the corresponding bodies and located between the heads and the base. The body comprises a hollow part for fixedly receiving a bolt. The hollow part comprises an expandable portion at a bottom end thereof, a smooth guiding portion above and adjacent the expandable portion, and a threaded portion above and adjacent the guiding portion. The guiding portion guides the bolt in the standoff to facilitate the bolt engaging in the threaded portion. The expandable portions are expanded to thereby combine the heat sink, standoffs and springs as a single unit.
Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of a preferred embodiment of the present invention with attached drawings, in which: